Is Remesh and Symmetry Option disabled if you have Multires Modifier on your mesh?

Hi guys, i’m new to blender. may i ask if you have a multires modifier, will Remesh and Symmetry become greyed out. for me it got greyed out, so i can’t remesh if the polygons are already too far stretched.

also, in the symmetry i can’t click the symmetrize x to -x.

Use of multires modifier implies that no addition or suppression of mesh components is done on base mesh.
So, those remeshing operations are forbidden. That is intended behavior.

Just as @zeauro said, both functions won’t work but if you are to turn on Sculpt Base Mesh on the Multires Modifier, you will be able to use Symmetrize only since the changes will affect the base mesh too